1. Field of the Invention
The present invention relates to a magnetic compound having a ThMn12 type crystal structure with high anisotropy field and high saturation magnetization, and a method of producing the same.
2. Description of Related Art
The application of a permanent magnet has been spread in a wide range of fields including electronics, information and telecommunications, medical cares, machine tools, and industrial and automotive motors, and the demand for reduction in the amount of carbon dioxide emissions has increased. In such a situation, development of a high-performance permanent magnet has been increasingly expected along with the spread of hybrid vehicles, energy-saving in industrial fields, the improvement of power generation efficiency, and the like.
A Nd—Fe—B magnet which is currently predominant in the market as a high-performance magnet is used as a magnet for a drive motor of a HV/EHV. Recently, it has been required to further reduce the size of a motor and to further increase the output of a motor (to increase the residual magnetization of a magnet). Accordingly, the development of a new permanent magnet material has been progressing.
In order to develop a material having higher performance than a Nd—Fe—B magnet, a study regarding a rare earth element-iron magnetic compound having a ThMn12 type crystal structure has been carried out. For example, Japanese Patent Application Publication No. 2004-265907 (JP 2004-265907 A) proposes a hard magnetic composition which is represented by R(Fe100-y-wCowTiy)xSizAv (wherein R represents one element or two or more elements selected from rare earth elements including Y in which Nd accounts for 50 mol % or higher of the total amount of R; A represents one element or two elements of N and C; x=10 to 12.5; y=(8.3-1.7×z) to 12; z=0.2 to 2.3; v=0.1 to 3; and w=0 to 30) and has a single-layer structure of a phase having a ThMn12 type crystal structure.
In the currently proposed compound which has a NdFe11TiNx composition having a ThMn12 type crystal structure, anisotropy field is high; however, saturation magnetization is lower than that of a Nd—Fe—B magnet and does not reach the level of a magnet material.